A constitutive model for sintering of granulated ceramic powders

Sintering behavior of granulated powder is investigated to develop a constitutive model for deformation analysis of ceramic powder compacts during sintering. Spray-dried alumina is compacted by CIPing (cold isostatic pressing) and sintered at various temperatures. Shrinkage and the change in grain size of the compacts during sintering are revealed in relation to the inhomogeneous microstructure consisting of fractured and unfractured granules as a consequence of the compaction. A constitutive model for the ceramic powder compacts having the internal structure is presented. The difference in grain growth in dense and sparse regions of the compacts is taken into consideration to the model. The results calculated by the model show good agreement with that obtained by experiment.